In recent years, besides conventional wire communication, attention has been focused on wireless communication that is more convenient. In wireless communication, a technique (diversity technique) is available in which plural antennas are provided and used in communication for the purpose of expanding a communication area or suppressing an effect of an interference wave.
In such a network including (i) an access point having plural antennas and (ii) plural stations, when broadcasting data to the stations, the access point is required to select, among the antennas, an antenna for use in broadcasting data to the stations. The conventional method for selecting an antenna for broadcasting includes a method of detecting, for each of the antennas of the access point, the number of errors in data (signals) received by the access point through the antenna, and selecting the antenna having less errors from among the antennas (see Patent Literature (PTL) 1).